Windshields, also known as windscreens, are among the most important safety elements in vehicles because they are the windows through which drivers view most traffic. Thus an essential function is provided when wipers clear these windows of rain, dew, dust, heavy pollen, insect residues, bird droppings, and fallen botanical detritus. Typical wipers are loosely stationary when at rest; this is helpful for accommodating their free wiping movement when the wiper is activated, but also causes inconveniences that in some cases pose a safety hazard.
Because of the loose character of wipers at rest, enterprising persons commonly place unsolicited coupons, advertisements, promotional flyers, or other unwanted literature under the windshield wipers of unattended automobiles that are in parking lots or along the edges of streets. Those papers must be removed before safe driving can ensue, indeed if the papers are torn off by the slipstream while the vehicle is in transit they represent a potential hazard for other drivers, also. However drivers who return to their vehicles after such papers are placed may not notice them until the vehicle is already moving along a highway or surface street at a high speed, when they flap in a distracting way but it is no longer convenient to reach out to remove the offending document or when the vehicle is no longer in a safe neighborhood. The failure to notice such literature before departing from the parking spot is particularly common after dark.
In addition, vandals commonly steal windshield wiper blades or the wiper arm itself. The easy deconstruction of the blade assembly and loose placement of the wiper assembly allows this to be done quickly and without the perpetrators drawing attention to themselves. It can be surprisingly expensive for the true owner to replace those parts. And when such thefts occur shortly before an owner must drive the vehicle to an appointment in a downpour or ice storm along a route where windshield wipers cannot be bought conveniently, the owners must often choose between the enhanced risk of driving and the consequences of missing the appointment.
Moreover, the looseness of the wiper assembly also allows leaves, pine needles and other natural detritus to accumulate at the interface of the windshield and wiper blade; the debris is commonly then pinned between the windshield and the wiper blade due to a slight excess in the blade's arch. When the wiping mode is activated while such debris is trapped there, the sweep of the blade is far less efficient at removing water or ice from the windshield, substantially compromising visibility for driving. And detritus that is carried along beneath the wiper blade in the sweep of the wiper also increases the wear on the blade, shortening its useful lifecycle. This affects both the cost and the safety of their use.
Thus there is an important ongoing need for means to constrain windshield wipers in a fixed position when vehicles are parked.